[PATCH] powerpc: G4+ oprofile support

This patch adds oprofile support for the 7450 and all its multitudinous
derivatives.

* Added 7450 (and derivatives) support for oprofile
* Changed e500 cputable to have oprofile model and cpu_type fields
* Added support for classic 32-bit performance monitor interrupt
* Cleaned up common powerpc oprofile code to be as common as possible
* Cleaned up oprofile_impl.h to reflect 32 bit classic code
* Added 32-bit MMCRx bitfield definitions and SPR numbers

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 206 insertions, 0 deletions

diff --git a/arch/powerpc/oprofile/op_model_7450.c b/arch/powerpc/oprofile/op_model_7450.c
new file mode 100644
index 000000000000..32abfdbb0eb1
--- /dev/null
+++ b/arch/powerpc/oprofile/op_model_7450.c
@@ -0,0 +1,206 @@
+/*
+ * oprofile/op_model_7450.c
+ *
+ * Freescale 745x/744x oprofile support, based on fsl_booke support
+ * Copyright (C) 2004 Anton Blanchard <anton@au.ibm.com>, IBM
+ *
+ * Copyright (c) 2004 Freescale Semiconductor, Inc
+ *
+ * Author: Andy Fleming
+ * Maintainer: Kumar Gala <galak@kernel.crashing.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/oprofile.h>
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <asm/ptrace.h>
+#include <asm/system.h>
+#include <asm/processor.h>
+#include <asm/cputable.h>
+#include <asm/page.h>
+#include <asm/pmc.h>
+#include <asm/oprofile_impl.h>
+
+static unsigned long reset_value[OP_MAX_COUNTER];
+
+static int oprofile_running;
+static u32 mmcr0_val, mmcr1_val, mmcr2_val;
+
+#define MMCR0_PMC1_SHIFT        6
+#define MMCR0_PMC2_SHIFT        0
+#define MMCR1_PMC3_SHIFT        27
+#define MMCR1_PMC4_SHIFT        22
+#define MMCR1_PMC5_SHIFT        17
+#define MMCR1_PMC6_SHIFT        11
+
+#define mmcr0_event1(event) \
+        ((event << MMCR0_PMC1_SHIFT) & MMCR0_PMC1SEL)
+#define mmcr0_event2(event) \
+        ((event << MMCR0_PMC2_SHIFT) & MMCR0_PMC2SEL)
+
+#define mmcr1_event3(event) \
+        ((event << MMCR1_PMC3_SHIFT) & MMCR1_PMC3SEL)
+#define mmcr1_event4(event) \
+        ((event << MMCR1_PMC4_SHIFT) & MMCR1_PMC4SEL)
+#define mmcr1_event5(event) \
+        ((event << MMCR1_PMC5_SHIFT) & MMCR1_PMC5SEL)
+#define mmcr1_event6(event) \
+        ((event << MMCR1_PMC6_SHIFT) & MMCR1_PMC6SEL)
+
+#define MMCR0_INIT (MMCR0_FC | MMCR0_FCS | MMCR0_FCP | MMCR0_FCM1 | MMCR0_FCM0)
+
+/* Unfreezes the counters on this CPU, enables the interrupt,
+ * enables the counters to trigger the interrupt, and sets the
+ * counters to only count when the mark bit is not set.
+ */
+static void pmc_start_ctrs(void)
+{
+        u32 mmcr0 = mfspr(SPRN_MMCR0);
+
+        mmcr0 &= ~(MMCR0_FC | MMCR0_FCM0);
+        mmcr0 |= (MMCR0_FCECE | MMCR0_PMC1CE | MMCR0_PMCnCE | MMCR0_PMXE);
+
+        mtspr(SPRN_MMCR0, mmcr0);
+}
+
+/* Disables the counters on this CPU, and freezes them */
+static void pmc_stop_ctrs(void)
+{
+        u32 mmcr0 = mfspr(SPRN_MMCR0);
+
+        mmcr0 |= MMCR0_FC;
+        mmcr0 &= ~(MMCR0_FCECE | MMCR0_PMC1CE | MMCR0_PMCnCE | MMCR0_PMXE);
+
+        mtspr(SPRN_MMCR0, mmcr0);
+}
+
+/* Configures the counters on this CPU based on the global
+ * settings */
+static void fsl7450_cpu_setup(void *unused)
+{
+        /* freeze all counters */
+        pmc_stop_ctrs();
+
+        mtspr(SPRN_MMCR0, mmcr0_val);
+        mtspr(SPRN_MMCR1, mmcr1_val);
+        mtspr(SPRN_MMCR2, mmcr2_val);
+}
+
+#define NUM_CTRS 6
+
+/* Configures the global settings for the countes on all CPUs. */
+static void fsl7450_reg_setup(struct op_counter_config *ctr,
+                             struct op_system_config *sys,
+                             int num_ctrs)
+{
+        int i;
+
+        /* Our counters count up, and "count" refers to
+         * how much before the next interrupt, and we interrupt
+         * on overflow.  So we calculate the starting value
+         * which will give us "count" until overflow.
+         * Then we set the events on the enabled counters */
+        for (i = 0; i < NUM_CTRS; ++i)
+                reset_value[i] = 0x80000000UL - ctr[i].count;
+
+        /* Set events for Counters 1 & 2 */
+        mmcr0_val = MMCR0_INIT | mmcr0_event1(ctr[0].event)
+                | mmcr0_event2(ctr[1].event);
+
+        /* Setup user/kernel bits */
+        if (sys->enable_kernel)
+                mmcr0_val &= ~(MMCR0_FCS);
+
+        if (sys->enable_user)
+                mmcr0_val &= ~(MMCR0_FCP);
+
+        /* Set events for Counters 3-6 */
+        mmcr1_val = mmcr1_event3(ctr[2].event)
+                | mmcr1_event4(ctr[3].event)
+                | mmcr1_event5(ctr[4].event)
+                | mmcr1_event6(ctr[5].event);
+
+        mmcr2_val = 0;
+}
+
+/* Sets the counters on this CPU to the chosen values, and starts them */
+static void fsl7450_start(struct op_counter_config *ctr)
+{
+        int i;
+
+        mtmsr(mfmsr() | MSR_PMM);
+
+        for (i = 0; i < NUM_CTRS; ++i) {
+                if (ctr[i].enabled)
+                        ctr_write(i, reset_value[i]);
+                else
+                        ctr_write(i, 0);
+        }
+
+        /* Clear the freeze bit, and enable the interrupt.
+         * The counters won't actually start until the rfi clears
+         * the PMM bit */
+        pmc_start_ctrs();
+
+        oprofile_running = 1;
+}
+
+/* Stop the counters on this CPU */
+static void fsl7450_stop(void)
+{
+        /* freeze counters */
+        pmc_stop_ctrs();
+
+        oprofile_running = 0;
+
+        mb();
+}
+
+
+/* Handle the interrupt on this CPU, and log a sample for each
+ * event that triggered the interrupt */
+static void fsl7450_handle_interrupt(struct pt_regs *regs,
+                                    struct op_counter_config *ctr)
+{
+        unsigned long pc;
+        int is_kernel;
+        int val;
+        int i;
+
+        /* set the PMM bit (see comment below) */
+        mtmsr(mfmsr() | MSR_PMM);
+
+        pc = mfspr(SPRN_SIAR);
+        is_kernel = (pc >= KERNELBASE);
+
+        for (i = 0; i < NUM_CTRS; ++i) {
+                val = ctr_read(i);
+                if (val < 0) {
+                        if (oprofile_running && ctr[i].enabled) {
+                                oprofile_add_pc(pc, is_kernel, i);
+                                ctr_write(i, reset_value[i]);
+                        } else {
+                                ctr_write(i, 0);
+                        }
+                }
+        }
+
+        /* The freeze bit was set by the interrupt. */
+        /* Clear the freeze bit, and reenable the interrupt.
+         * The counters won't actually start until the rfi clears
+         * the PMM bit */
+        pmc_start_ctrs();
+}
+
+struct op_powerpc_model op_model_7450= {
+        .reg_setup              = fsl7450_reg_setup,
+        .cpu_setup              = fsl7450_cpu_setup,
+        .start                  = fsl7450_start,
+        .stop                   = fsl7450_stop,
+        .handle_interrupt       = fsl7450_handle_interrupt,
+};